Supported polymerization catalyst

ABSTRACT

A catalyst useful in the polymerization of olefins is disclosed. The catalyst is produced by initially treating an inert inorganic compound to remove surface hydroxy groups. The thus treated inorganic compound is contacted with a hydrocarbon soluble magnesium compound in a second step. The product of this second step is contacted with a modifying compound selected from the group consisting of silicon halides, boron halides, aluminum halides, alkyl silicon halides, hexaalkyl disilazanes and mixtures thereof in a third step. The product of this third step is contacted a vanadium compound having the structured formula V(O) s  X 1   4-s , where X 1  is halogen; and s is 0 or 1, a first titanium-containing compound having the structural formula Ti(OR 2 ) n  X 2  m, where R 2  is hydrocarbyl; X 2  is halogen; n is an integer of 1 to 4; and m is 0 or an integer of 1 to 3, with the proviso that the sum of n and m is 4, and a second titanium-containing compound having the structural formula TiX 3  (OR 3 ) q , where X 3  is halogen; R 3  is hydrocarbyl; p is an integer of 1 to 4; and q is 0 or an integer of 1 to 3, with the proviso that the sum of p and q is 4 and that the first and the second titanium-containing compounds are not identical. 
     A process for polymerizing olefins, using the catalyst of this disclosure is also provided.

This is a divisional of copending application Ser. No. 498,313, filed onMar. 23, 1990.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The instant invention is directed to a catalyst useful in thepolymerization of olefins. More particularly, the instant invention isdirected to a catalyst, useful in the polymerization of olefins, whereinmagnesium, vanadium and titanium compounds are disposed on an inertsupport.

2. Background of the Prior Art

The polymerization of olefins using Ziegler-Natta catalysts is almostuniversely employed. These catalysts provide polyolefins having desiredcharacteristics in high yield. However, because of the myriadapplications to which polyolefins are used, no single class of catalystprovides polymers having the specific desired utility.

A characteristic, however, common to many olefin polymerizationcatalysts in the prior art is the incorporation therein of internalelectron donors. These compounds are utilized in applications whichrequire high isotacticity. The presence of internal electron donors,however, creates difficulties in the use of the catalyst and the productproduced. Those skilled in the art are aware that unless the amount andtype of electron donor compound is carefully selected not only isstereoregularity of the resultant polymer deficient but poor catalyticactivity often results. This detrimental effect occurs even if thecatalyst is formed with the proper electron donor compound in thecorrect concentration added in the wrong sequence.

The utilization of electron donor compounds often create additionalproblems involving offensive odors in the final polymeric product. Thisunfortunate result obtains even if the ideal electron donor, provided inthe correct concentration and introduced in proper sequence in thecatalyst formation process, is utilized. Thus, polymers formed fromcatalysts which include an electron donor compound must oftentimes bedeashed or deodorized in order to insure that there is no odor given offby the final polymeric product.

Another disadvantage identified in the prior art is the use of magnesiumhalide supports. Such supports are commonly utilized in thepolymerization of propylene. This important class of olefins isoftentimes polymerized by a magnesium halide supported catalyst becauseof the advantageous results noted with such catalysts. Unfortunately,the use of such a support has adverse effects.

These adverse effects are partially ascribable to the corrosive natureof this compound. Molding machines which process polymers formed frompolymerizations catalyzed by magnesium halide supported catalysts aresubject to corrosion due to the corrosive nature of the polymer whichincludes magnesium halide supported catalyst therein. Moreover, theadverse effect of this corrosion is not limited to damage to expensivemolding machinery. Equally significant, the polyolefinic molded articleprocessed by this molding machinery is in many cases characterized byaesthetic flaws.

Very recently, a patent application assigned to the assignee of thepresent application was developed which addressed the issues discussedabove. That is, a new catalyst was developed which produces olefinicpolymers, particularly propylene polymers, of high stereoregularity,uniform particle size distribution, good spherical morphology and highbulk density. Although this invention, embodied in U.S. patentapplication, Ser. No. 326,708, filed Mar. 21, 1989, which is acontinuation of U.S. patent application, Ser. No. 99,190, filed Sept.21, 1988, now abandoned, also represents an advance in the art in termsof olefinic polymer productivity, that catalyst does not produce apolymer that can rapidly be processed in such applications as injectionmolded applications to produce products in the high rate required forcommercialization.

The above remarks establish that there is a continuing need in the artfor catalysts useful in the polymerization of olefins that not onlyeliminate the problems associated with corrosive supports and theformation of catalysts utilizing internal electron donors but, inaddition, produce olefinic polymers having melt indeces or melt flowrates such that injected molded products can be produced in high yield.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to catalysts having excellentcharacteristics which, in addition, when added to olefin polymerizationreactors, produce olefinic polymers which are characterized by meltindeces and melt flow rates in a range such that injected moldingoperations using such polymers are optimized.

In accordance with the present invention, a catalyst is provided. Thecatalyst comprises a product obtained by treating an inert inorganic toremove an surface hydroxyl groups thereon. The thus treated inertinorganic compound is contacted with at least one hydrocarbon solublemagnesium compound. The product of this contact is, in turn, contactedwith a modifying compound selected from the group consisting of siliconhalides, boron halides, aluminum halides, alkyl silicon halides andmixtures thereof. The product of this contact is next contacted with ahalogen-containing vanadium compound having the structural formulaV(O)_(s) X¹ _(4-s), where X¹ is halogen; and s is 0 or 1; a firsttitanium-containing compound having the structural formula Ti(OR²)_(n)X² _(m), where R² is hydrocarbyl, X² is halogen; n is an integer of 1 to4; and m is 0 or an integer of 1 to 3 with the proviso that the sum of nand m is 4; and a second-containing titanium compound having thestructural formula TiX³ _(p) (OR³)_(q) where X³ is halogen; R³ ishydrocarbyl; p is an integer of 1 to 4; and q is 0 or an integer of 1 to3 with the provisos that the sum of p and q is 4 and that the first andthe second titanium-containing compounds are not identical.

In another aspect of the present invention, a process for polymerizingan olefin is disclosed. In this process at least one olefin ispolymerized under olefinic polymerization conditions utilizing thecatalyst of the present invention along with a first co-catalyst, analuminum-containing compound, and a second co-catalyst, a silanecompound.

DETAILED DESCRIPTION

The catalyst of the present invention is prepared by treating an inertinorganic compound, preferably selected from the group consisting ofsilica, alumina, titania and zirconia, of which silica is mostpreferred, to remove surface hydroxyl groups. To this end, the treatmentof the inorganic compound involves either subjecting the inert inorganiccompound to elevated temperature in an inert atmosphere or to initiallycontacting the inert inorganic compound with hexamethyldisilazanefollowed by the aforementioned heating step.

The heating step utilized in the treatment of the inert inorganiccompound involves exposure of the inorganic compound to a temperature inthe range of between about 100° C. and about 150° C. for a period in therange of between about 30 minutes and 3 hours. Preferably, the heatingstep occurs at a temperature in the range of between about 100° C. andabout 135° C. for a period in the range of between about 40 minutes andabout 2 hours. Most preferably, the heating step involves exposure ofthe inert inorganic compound to a temperature in the range of betweenabout 100° C. and 120° C. for a period in the range of between about 45minutes and about 1.5 hours. In order to ensure an inert environment, itis preferred that this heating step occur in an inert gas atmosphere.Preferably, the inert gas is provided by nitrogen.

The thus treated inert inorganic compound, utilized as the support forthe catalyst, is contacted with at least one hydrocarbon solublemagnesium compound in the second step of the process of forming thecatalyst of the present invention. The hydrocarbon soluble magnesiumcompound is preferably characterized by the structural formula

    Mg(OR).sub.r X.sub.t                                       (I)

where R is hydrocarbyl; X is halogen; r is 1 or 2; and t is 0 or 1. Morepreferably, R is C₁ -C₁₂ alkyl; X is bromine or chlorine. Even morepreferably, structural formula I is characterized by R being C₄ -C₁₀alkyl; X being chlorine; and r and s being 1. Among the preferredhydrocarbon soluble magnesium compounds contemplated for use in theformation of the catalyst of this invention are2-methylpentyloxymagnesium chloride, pentyloxymagnesium chloride,di-2-ethylhexyloxymagnesium and the like.

The contact between the treated inert inorganic compound utilized as asupport and the hydrocarbon soluble magnesium compound occurs atelevated temperature. Preferably, the temperature of this contact is inthe range of between about 40° C. and about 130° C. More preferably, thetemperature of this contact is in the range of between about 50° C. andabout 120° C. The duration of this contact is in the range of betweenabout 20 minutes and about 5 hours. Preferably, the duration of thecontact between the magnesium compound and the inert inorganic supportcompound is in the range of between about 1 hour and about 4 hours. Morepreferably, the duration of this contact is in the range of betweenabout 2 hours and about 3 hours.

In a particularly preferred embodiment of the present invention contactbetween the magnesium compound and the inorganic compound occurs indiscrete heating steps. That is, the temperature of contact is initiallyin the range of between about 40° C. and about 80° C. Contact at thistemperature range occurs over a period in the range of between about 10minutes and about 1 hour. This is followed by contact at a temperaturein the range of between about 60° C. and about 100° C., again for aperiod in the range of between about 10 minutes and about 1 hour.Finally, the temperature is again raised to between about 80° C. andabout 120° C. for a period of 1 to 2 hours. In this latter heating stepthe solvent, in which, in a preferred embodiment, the hydrocarbonsoluble magnesium compound is dissolved, is distilled off. Contactterminates with the removal of all the solvent. At this point theproduct, a solid having flour-like consistency, is cooled to ambienttemperature.

In the third step of the process of forming the catalyst, the product ofthe second step, a solid having flour-like consistency, is contactedwith a modifying compound selected from the group consisting of siliconhalides, boron halides, aluminum halides, alkyl silicon halides andmixtures thereof. Of these modifying compounds, silicon halides, boronhalides and aluminum halides are preferred. Of these preferred halides,the chlorides are particularly preferred. Thus, silicon tetrachloride,boron trichloride, and aluminum trichloride are particularly preferred.Of these, silicon tetrachloride is most preferred.

The contact between the modifying compound or compounds and the productof the second step of the process of forming the catalyst of thisinvention, the contact between the inert inorganic compound and thesoluble magnesium compound, occurs at a temperature in the range ofbetween about 15° C. and about 100° C. over a period in the range ofbetween about 15 minutes and about 3 hours. More preferably, thiscontact occurs at a temperature in the range of between about 20° C. andabout 80° C. for a period in the range of between about 30 minutes andabout 2 hours.

In a particularly preferred embodiment, just as in the second step, thisthird step occurs in temperature sequences. In this step, twotemperature sequences are utilized. The first temperature sequence,which occurs over a period of between about 10 minutes and about 1.5hours, involves contact of the modifying compound and the product of thesecond step at a temperature in the range of between about 15° C. andabout 50° C. This is followed by contact for an equal period of time,about 10 minutes to about 1.5 hours, at a temperature in the range ofbetween about 30° C. and about 100° C.

It is noted that, as in the second step where the soluble magnesiumcompound is preferably introduced as a solution, the modifying compoundis also preferred contacted in solution. In a preferred embodiment thesolvent is a hydrocarbon, preferably an alkane containing 5 to 9 carbonatoms. In a particularly preferred embodiment of the present inventionthis solvent is heptane. It is emphasized that the solvent preferred foruse in the second step, wherein the soluble magnesium compound isintroduced as a solution also utilizes a hydrocarbon solvent, preferablyan alkane containing 5 to 9 carbon atoms. Again, in that step heptane isparticularly preferred.

Upon completion of this contact, heating is turned off and the solidproduct of this contact is allowed to settle in the liquid in which itis disposed. The liquid, in a preferred embodiment, is thereuponremoved. Any method of liquid removal, such as decantation, can beutilized. However, in a preferred embodiment, siphoning is employed toremove the liquid above the solid.

In a preferred embodiment the product of this third step is washed.Washing involves the addition of an organic solvent which removesorganic impurities. The organic solvent is preferably a hydrocarbon.More preferably, the solvent is an alkane containing 5 to 9 carbonatoms. Most preferably, the alkane is heptane.

In the preferred embodiment where in the product of the third step issubject to washing, the organic solvent is added to the solids in anamount sufficient to completely immerse the solid product therein.During contact between the solvent and the solid product of the thirdprocessing step stirring is preferably provided. The solvent and thesolids are contacted in this first preferred washing step for about 1 toabout 10 minutes. Upon completion of this time the solids are allowed tosettle to the bottom of the slurry. Thereupon, the organic solvent isremoved by any suitable method such as decantation or siphoning.Preferably, the liquid is removed by siphoning.

The above first preferred washing procedure is repeated. Typically, thiswashing procedure is repeated for a total of between about 2 and about 5times. Three duplications of this first preferred washing step areparticularly preferred.

Whether the product of the third step in the catalyst forming process iswashed or not, the next essential step, the fourth processing step,involves contact of the washed or unwashed product with avanadium-containing compound having the structural formula

    V(O).sub.s X.sup.1.sub.4-s                                 (II)

where X¹ is halogen; and s is 0 or 1. In a preferred embodiment, X¹ isfluorine, chlorine or bromine. Of these, bromine and chloride arepreferred, with chlorine being most preferred. It is particularlypreferred that the vanadium compound be vanadium oxychloride or vanadiumtetrachloride.

The washed or unwashed product of the third processing step is alsocontacted, in this fourth step, with a first titanium-containingcompound having the structural formula

    Ti(OR.sup.2).sub.n X.sup.2.sub.m                           (III)

R² is hydrocarbyl; X is halogen; n is an integer of 1 to 4; and m is 0or an integer of 1 to 3 with the proviso that the sum of n and m is 4.Thus, the titanium compound having the structural formula IIIencompasses tetrahydrocarbyloxytitaniums, trihydrocarbyloxytitaniumhalides, dihydrocarbyloxytitanium dihalides and hydrocarbyloxytitaniumtrihalides.

More preferably, compound III is characterized by R² being alkyl, aryl,aralkyl or alkaryl; n is 4 and m is 0. Still more preferably, R² isalkyl or alkaryl.

Among the particularly preferred titanium compounds within thecontemplation of structural formula III are tetracresyltitanate,titanium tetrabutoxide, titanium tetranonolate,tetra-2-ethylhexyltitanate, tetraisobutyltitanate,tetra-n-propyltitanate, tetraisopropyltitanate and the like. Of thesecompounds tetracresyltitanate is particularly preferred.

In addition to the vanadium-containing compound, having the structuralformula II, and the first titanium-containing compound, having thestructural formula III, contact of the product of the third processingstep, in this fourth step, also occurs with a second titanium-containingcompound having the structural formula

    TiX.sup.3.sub.p (OR.sup.3).sub.q                           (IV)

where X³ is halogen; R³ is hydrocarbyl; p is an integer of 1 to 4; and qis 0 or an integer of 1 to 3 with the proviso that the sum of p and q is4. Although this second titanium-containing compound encompassestitanium tetrahalides, hydrocarbyloxytitanium trihalides,dihydrocarbyloxytitanium dihalides and trihydrocarbyloxytitaniumhalides, it is emphasized that the two titanium-containing compoundshaving the structural formulae III and IV are not identical.

In a preferred embodiment, the titanium compound having the structuralformula IV is characterized by X³ being chlorine or bromine; p being 4;and q being 0. Of the two compounds within the contemplation of thispreferred embodiment, titanium tetrachloride and titanium tetrabromide,titanium tetrachloride is particularly preferred.

In this fourth step where the product of the third processing step iscontacted with compounds having the structural formulae II, III and IV,the order or sequence of contact is immaterial. That is, in onepreferred embodiment all three compounds are contacted with the productof the third processing step simultaneously or as a mixture. In a secondpreferred embodiment, the vanadium compound initially contacts theproduct of the third step followed by contact with the firsttitanium-containing compound and thereafter by the secondtitanium-containing compound. In another preferred embodiment thissequence is reversed, that is, the second titanium-containing compoundinitially contacts the product of the third step followed by the firsttitanium-containing compound and lastly by the vanadium-containingcompound. In yet another embodiment of the present invention, contactoccurs between the product of the third step and the firsttitanium-containing compound followed by the vanadium compound andterminating with contact with the second titanium-containing compound.It is unnecessary to go through the other possible combinations. Sufficeit to say, any order of contacting of the three compounds is within thecontemplation of the present invention. Of these methods of contact,sequential contact with the vanadium compound, the first titaniumcompound and the second titanium compound in that order is particularlypreferred.

In the preferred embodiment wherein all three compounds are addedsimultaneously or as a mixture, contact occurs over a period of betweenabout 15 minutes and about 3 hours at a temperature in the range ofbetween about 40° C. and about 140° C. Preferably, the duration ofcontact is in the range of between about 30 minutes and about 2 hours ata temperature in the range of between about 60° C. and about 120° C.More preferably, the duration of contact is in the range of betweenabout 45 minutes and about 1.5 hours at a temperature in the range ofbetween about 80° C. and about 100° C.

In the preferred embodiment wherein the three compounds contact theproduct of the third processing step in sequence, independent of theorder of contact, the first step involves contact of the product of thethird processing step with the first contacting compound over a periodof between about 30 seconds and about 5 minutes. The product of thiscontact is in turn contacted with a second contacting compound over aperiod of between about 2 minutes and about 10 minutes. Both of thesefirst two contacts preferably occur at ambient temperature. The finalstep, the addition of the third contacting compound occurs over aduration and a temperature range substantially identical with thatutilized when the three contacting compounds are introducedsimultaneously.

The three contacting compounds may be added near or as a solution. In apreferred embodiment, the vanadium-containing compound and the secondtitanium-containing compound contact the product of the third step or aproduct of contact with that product is the pure compound, that is neat.The first titanium-containing compound preferably contacts the productof the third processing step or a product of contact with that productin solution. Preferably, the solvent of that solution is a hydrocarbon,preferably an alkane having 5 to 9 carbon atoms. Most preferably, thatalkane is heptane.

Independent of the method of contact of the three compounds with theproduct of the third step, the product of this fourth step is preferablywashed. In the preferred embodiment, where washing of the product of thefourth step occurs, the procedure for washing is identical with theprocedure for washing the product of the third processing step. However,whereas the first washing step occurs in 2 to 5 stages, the preferredsecond washing step, the washing of the solids of the product of thefourth processing step, occurs, in a preferred embodiment, in about 5 toabout 10 washing stages, i.e., separate charges of organic solvent.

The following examples are given to illustrate the scope of the presentinvention. Because these examples are given for illustrative purposesonly, the invention embodied herein should not be limited to theseexamples.

EXAMPLE 1 Preparation of Catalyst

Silica (5 g.) pretreated with hexamethyldisilazane, was disposed in a250 ml., three-necked round bottomed flask equipped with a nitrogenpurge, a paddle stirrer, a heptane inlet, a nitrogen inlet, athermometer and a siphon. Upon the addition of the silica, nitrogen wasslowly introduced into the flask to provide a nitrogen atmosphere. Theflask and its contents were then heated to 110° C. for one hour.Thereupon, the flask and its silica-containing contents were cooled toambient temperature.

To the flask was added 2-methylpentyloxymagnesium chloride (45 ml. of an0.9M solution in heptane). The thus formed slurry was heated ar 60° C.for 30 minutes followed by increasing the temperature to 80° C. whichwas maintained for an additional 30 minutes. Thereafter, the temperaturewas raised to 100° C. until all the solvent was distilled off. At thispoint, the solid product had a flour-like consistency. The heating stepat 100° C. to remove all the solvent took approximately 1.5 hours. Allthese contacting steps occurred with stirring. At the termination ofcontact at 100° C., stirring was stopped and the flask and its contentscooled to ambient temperature.

The cooled product in the flask was next contacted with heptane (20 ml.)followed by the addition of silicon tetrachloride (4.5 ml.). The thusformed slurry was stirred and the contents of the flask heated for 30minutes at 25° C. At this point, the temperature was increased to 60° C.and heating continued for an additional 30 minutes. At this point,heating was stopped and the stirrer was turned off.

The cooled solid in the flask was allowed to settle. The liquid abovethe solid was siphoned off and heptane (70 ml.) added thereto. Stirringat room temperature was initiated and continued for 5 minutes. Thereuponthe solids in the slurry were allowed to settle. The heptane wassiphoned off and the washing procedure was repeated. Three such washingssequences were conducted.

The washed product, a solid, was then contacted with vanadiumoxychloride (0.1 ml.) at ambient temperature and mixed therewith for oneminute. Thereupon, tetracresyltitanate (3.0 ml., introduced as a 50volume percent solution in heptane) was added. Mixing was initiated andcontinued for 5 minutes, again at ambient temperature. At that time,titanium tetrachloride (10 ml.) was added. The resultant slurry wasstirred and heating was turned on. The contents of the flask were heatedat a temperature of 90° C. This heating, with stirring, continued forone hour. At that C. time, the heating was turned off and stirring wasstopped. The liquid contents of the flask were then removed by siphon.

The solid product remaining was washed about 9 times with heptane (80ml. in each wash sequence) in accordance with the procedure recitedabove. That is, each washing sequence constituted charging heptane tothe solids, mixing the resultant slurry, which was continued for about 5minutes, followed by settling of the solids and removing the solvent bysiphoning.

The product of this process was analyzed to determine its elementalconstituency. This analysis is included in Table 1.

EXAMPLE 2 Preparation of Catalyst

A catalyst was prepared utilizing the procedure of Example 1 except thatthe volume of vanadium oxychloride added to the product of contact ofthe third processing step was 0.2 ml., rather than the 0.1 ml.introduced in Example 1.

An elemental analysis of the product of Example 2 is included in Table1.

EXAMPLE 3 Preparation of Catalyst

A catalyst was prepared in exact accordance with the procedure ofExample 1 except that the volume of vanadium oxychloride liquid utilizedin this example was 0.4 ml. rather than the 0.1 ml. utilized in Example1.

An elemental analysis of the product of Example 3 is included in Table1.

COMPARATIVE EXAMPLE 1 Preparing of a Non-Inventive Catalyst

A catalyst was made in accordance with Example 1 except that the washedproduct of the third processing step, the product of contact withsilicon tetrachloride, was contacted with 10 ml. vanadium oxychloriderather than the 0.1 ml. utilized in Example 1. Moreover, neithertetracresyltitanate nor titanium tetrachloride were contacted with theproduct of the third contacting step. That is, the fourth contactingstep included only the inclusion of vanadium oxychloride. The excessvanadium oxychloride was removed in the washings which occurredsubsequent to the addition of the contact with vanadium oxychloride.

An analysis of the product of this example is included in Table 1.

COMPARATIVE EXAMPLE 2 Preparation of a Prior Art Catalyst

A catalyst was produced in accordance with the procedure of Example 1except that vanadium oxychloride was omitted from contact with theproduct of the third contacting step. It is emphasized that the additionof tetracresyltitanate and titanium tetrachloride were in accordancewith the procedure utilized in Example 1.

An elemental analysis of the catalytic product of Comparative Example 2appears in Table 1.

                  TABLE 1                                                         ______________________________________                                        Elemental Analysis of Catalysts                                               Catalyst                                                                      of Example No.                                                                           Mg, % by Wt                                                                              Ti, % by Wt V, % by Wt                                  ______________________________________                                        1          7.8        4.2         1.4                                         2          6.8        3.6         2.0                                         3          4.2        3.9          2.75                                       CE1        1.8                                                                0-         10.5                                                               CE2        4.2        3.9                                                     0-                                                                            ______________________________________                                    

EXAMPLE 4 Polymerization of Propylene

A reactor was initially purged with nitrogen. To the purged reactor wasadded heptane (20 ml.), followed by the introduction of triethylaluminum(0.8 ml., introduced as a 1.5M solution in heprane).Isobutylisopropyldimethoxysilane (0.1 ml., introduced as a 1M solutionin heptane) was next charged into the reactor followed by the chargingof the solid catalyst of Example 1 (20 mg.). Hydrogen gas (200 ml.) wasintroduced into the reactor from an 80 psig pressurized hydrogen gascylinder. Finally, propylene (325 g.) was added to the reactor.

The reactor was pressurized to 460 psig. and heated to 70° C. Thecontents of the reactor were stirred by a stirrer rotating at 400revolutions per minute. These conditions were maintained for one hourduring which time the propylene was polymerized to polypropylene.

The weight of polypropylene polymerized, its insolubility in heptane,measured as a percent by weight, and its melt flow rate, as measured byASTM D-1238, is summarized in Table 2. It is emphasized that each of thetabulated results are an average of two runs.

EXAMPLES 5 and 6 and COMPARATIVE EXAMPLES 3 and 4 Polymerization ofPropylene

Polymerizations conducted in accordance with the procedure of Example 4,were conducted employing the catalysts produced in accordance withExamples 2 and 3 and Comparative Examples 1 and 2. As in Example 4, eachof these polymerization experiments were repeated.

The results of the average results of two runs are reported in Table 2.

                  TABLE 2                                                         ______________________________________                                                                       Heptane Melt                                   Polymerization                                                                          Catalyst  Activity,  Insol., Flow                                   Example No.                                                                             of Ex. No.                                                                              gPP/gCat-Hr                                                                              % by Wt.                                                                              Rate                                   ______________________________________                                        4         1         11,500     97.8    *                                      5         2          9,650     95.6    2.96                                   6         3         12,000     95.7    3.75                                   CE3       CE1       No Polymerization Occurred                                CE4       CE2       10,000     96.0    2.0                                    ______________________________________                                         *Not Measured                                                            

The above embodiments and examples are given to illustrate the scope andspirit of the instant invention. These embodiments and examples willmake apparent, to those skilled in the art, other embodiments andexample. These other embodiments and examples are within thecontemplation of the present invention. Therefore, the present inventionshould be limited only by the appended claims.

What is claimed is:
 1. A process for making an olefinic polymercomprising polymerizing at least one olefin under olefin polymerizationconditions in the presence of(I) a cavity component comprising theproduct produced by the steps of(a) treating an inert inorganic compoundto remove surface hydroxyl groups; (b) contacting the treated inertinorganic compound with a hydrocarbon soluble magnesium compound; (c)contacting the product of said step (b) with a modifying compoundselected from the group consisting of silicon halides, boron halides,aluminum halides, alkyl silicon halides, hexaalkyl disilazanes andmixtures thereof; and (d) contacting the product of said step (c) with avanadium compound having the structural formula V(O)₂ X¹ _(4-s), ishalogen and s is 0 or 1; a first titanium-containing compound having thestructural formula Ti(OR²)_(n) X² _(m), where R² is hydrocarbyl, X² ishalogen, n is an integer of 1 to 4, and m is 0 or an integer of 1 to 3with the priviso that the sum of n and m is 4; and a secondtitanium-containing compound having the structural formula TiX³ _(p)(OR³)_(q), where ³ is halogen, R³ is hydrocarbyl, p is an integer of 1to 4, and q is 0 or an integer of 1 to 3, with the provisos that the sumof p and q are 4 and that said first and said second titanium-containingcompounds are not identical; (II) an aluminum compound; and (III) asilane compound.
 2. A process in accordance with claim 1 wherein saidinert inorganic support is selected from the group consisting of silica,alumina, titania and zirconia.
 3. A process in accordance with claim 1wherein said treatment of step (a) comprises heating said inertinorganic support to a temperature in the range of between about 100° C.and about 150° C. for a period of between about 30 minutes to about 3hours.
 4. A process in accordance with claim 3 wherein said inertinorganic support is silica pretreated with hexamethyl disilazane priorto said heating step.
 5. A process in accordance with claim 1 whereinsaid hydrocarbon soluble magnesium compound has the structural formulaMg(OR)_(r) X_(t), where R is hydrocarbyl; X is halogen; r is 1 or 2; andt is 0 or
 1. 6. A process in accordance with claim 5 wherein R is C₁-C₁₂ alkyl; and X is chloride or bromine.
 7. A process in accordancewith claim 6 wherein R is C₄ -C₁₀ alkyl; X is chlorine; and r and tare
 1. 8. A process in accordance with claim 1 wherein said step (b)occurs at a temperature in the range of between about 40° C. and about130° C. for a period in the range of between about 20 minutes and about5 hours.
 9. A process in accordance with claim 1 wherein said modifyingcompound is selected from the group consisting of silicon halides, boronhalides and aluminum halides.
 10. A process in accordance with claim 9wherein said modifying compound is selected from the group consisting ofsilicon tetrachloride and silicon tetrabromide.
 11. A process inaccordance with claim 1 wherein said step (c) occurs at a temperature inthe range of between about 15° C. and about 100° C. over a period in therange of between about 15 minutes and about 3 hours.
 12. A process inaccordance with claim 1 wherein said product of said step (c) is washedwith an organic solvent.
 13. A process in accordance with claim 1wherein said vanadium compound is selected from the group consisting ofvanadium oxychloride and vanadium tetrachloride.
 14. A process inaccordance with claim 1 wherein said first titanium-containing compoundis characterized by R² being alkaryl or alkyl; n being 4; and m being 0.15. A process in accordance with claim 1 wherein said secondtitanium-containing compound is characterized by X³ being chlorine orbromine; p being 4; and q being
 0. 16. A process in accordance withclaim 1 wherein said step (d) occurs at a temperature in the range ofbetween about 40° C. and about 140° C. over a period in the range ofbetween about 15 minutes and about 3 hours.
 17. A process in accordancewith claim 1 wherein the product of step (c) is contacted with saidvanadium compound and said first and said second titanium-containingcompounds simultaneously or as a mixture.
 18. A process in accordancewith claim 1 wherein said vanadium compound and said first and saidsecond titanium-containing compounds contact said product of said step(c) consecutively in any order.
 19. A process in accordance with claim18 wherein said product of said step (c) is contacted with said vanadiumcompound, the product of which is contacted with said firsttitanium-containing compound which product is contacted with said secondtitanium-containing compound.
 20. A process in accordance with claim 1comprising washing said product of said step (d) with an organicsolvent.
 21. A process for making an olefinic polymer comprisingpolymerizing at least one olefin under olefin polymerization conditionsin the presence of(I) a catalyst component comprising the productproduced by the steps of:(a) heating silica to remove surface hydroxylgroups; (b) contacting the silica product of step (a) with a hydrocarbonsoluble magnesium compound having the structural formula Mg(OR)_(r)X_(t), where R is hydrocarbyl, X is halogen, r is 1 or 2, and t is 0 or1; (c) treating the product of step (b) with a modifying compoundselected from the group consisting of silicon halides boron halides andaluminum halides; and (d) contacting the product of step (c) with ahalogen-containing vanadium compound having the structural formulaV(O)_(s) X¹ _(4-s), X¹ is bromine or chlorine, and s is 0 or 1; atitanium ester having the structural formula Ti(OR²)₄, where R₂ is alkylor alkaryl, and a titanium halide having the structural formula TiX³ ₄,where X³ is bromine or chlorine; (II) an aluminum compound selected fromthe group consisting of an aluminum alkyl and an alkylaluminum halide;and (III) a silane compound having the structural formula R⁴ _(u)(OR⁵)_(4-u) Si, where R⁴ and R⁵ are the same or different and arehydrocarbyl, and u is an integer of 1 to
 3. 22. A process in accordancewith claim 21 wherein said silica is heated to a temperature in therange of between about 100° C. and about 135° C. for a period of betweenabout 40 minutes and about 2 hours.
 23. A process in accordance withclaim 22 wherein said silica is pretreated with hexamethyl disilazaneprior to said heating step.
 24. A process in accordance with claim 21wherein R is C₄ -C₁₀ alkyl; and X is chlorine.
 25. A process inaccordance with claim 24 wherein said hydrocarbon soluble magnesiumcompound is 2 methylpentyloxymagnesium chloride.
 26. A process inaccordance with claim 21 wherein said halogen-containing vanadiumcompound is selected from the group consisting of vanadium oxychlorideand vanadium tetrachloride; said titanium ester is tetracresyl titanate;and said titanium halide is titanium tetrachloride.
 27. A process inaccordance with claim 21 wherein said product of said step (d) is washedwith an alkane containing between about 5 and about 9 carbon atoms. 28.A process for making an olefinic polymer comprising polymerizing atleast one olefin under olefin polymerization conditions in the presenceof(I) a catalyst component comprising the product produced by the stepsof(a) heating silica at a temperature in the range of between about 100°C. and about 120° C. for a period in the range of between about 45minutes and about 1.5 hours; (b) contacting the heated silica with2-methylpentyloxymagnesium chloride initially at a temperature in therange of between about 40° C. and about 80° C. for a period in the rangeof between about 20 minutes and about 1 hour, followed by heating at atemperature in the range of between about 60° C. and about 100° C. for aperiod in the range of between about 10 minutes and about 1 hour,followed by heating at a temperature in the range of between about 80°C. and about 120° C. for a period in the range of between about 1 hourand about 2 hours. (c) contacting the product of step (b) with silicontetrachloride for a period of between about 10 minutes and about 1.5hours at a temperature in the range of between about 15° C. and about50° C., followed by a heating at a temperature in the range of between30° C. and about 100° C. for a period in the range of between about 10minutes and about 1.5 hours; and (d) contacting the product of step (c)with vanadium oxychloride at about ambient temperature for a period inthe range of between about 30 seconds to about 5 minutes, the product ofwhich is contacted with tetracresyl titanate for a period in the rangeof between about 2 minutes and about 10 minutes at about ambienttemperature, the product which is contacted with titanium tetrachlorideat a temperature in the range of between about 80° C. and about 100° C.for a period in the range of between about 45 minutes and about 1.5hours; (II) triethylaluminum; and (III)isobutylisopropyldimethoxysilane.
 29. A process in accordance with claim28 wherein said silica is pretreated with hexamethyldisilazane prior tosaid step (a).